1. Field of the Invention
The invention generally relates to devices for forming predetermined shapes in the ends of solid cylindrical articles of manufacture. More particularly, the invention relates to a cutting device for shaping one end of an oval cross-sectioned cylindrical solid antiperspirant product into a domed shape.
2. Description of the Prior Art
It is desirable to produce antiperspirant and other cosmetic and toiletry products in a form or shape adapted to comfortably apply the product to selected parts of the human body. While the invention is suitable for a variety of products which are moldable into a selected solid shape and used by being rubbed against a surface, this particular invention relates to shaping solid products such as antiperspirant or deodorant compositions. Solid forms of antiperspirant or deodorant products are generally produced by molding a liquid composition into a cylindrical solid stick form having a variety of cross-sections, usually circular, oval or elliptical. The stick is molded within a tubular dispenser shell which defines the cross-section of the product. Some mechanism is provided for advancing the stick from the shell and for retracting it after use.
This advancing/retracting mechanism comprises a platorm for holding one end of the stick and a means f or moving the platform relative to the container shell to expose the other end of the stick for use. While the product may simply be pushed from the shell, it is generally advanced by having the platform threaded on an axially positioned threaded rod which is rotated by means of a knurled knob. It is desirable that the end of the stick protruding from the shell and to be applied to the body be comfortably shaped, for example, generally hemispherical in the case of round sticks and domed in the case of oval or elliptically cross-sectional cylinders.
The dispenser shells may be filled using either the top-fill or the bottom-fill method. The bottom-fill method entails inverting the shell with a cap in place, filling it from the bottom with liquid product and then inserting the platform and its associated advancing components into the bottom of the shell so that the product supporting mechanism may set into the stick before it solidifies.
The top-fill method is simpler and more inexpensive than the bottom-fill method and requires fewer parts. In the top-fill method, the product container shell is entirely assembled except for the cap and liquid product is poured into the container from the top and sets into the supporting platform which is already inserted in the bottom of the container.
In both top-fill and bottom-fill methods additional steps need to be taken if the final product is desired to have a shaped exposed end. In a bottom-fill method, the desired shape may be produced by a shaping fitment which stays in the cap of the product and is removed by the customer prior to use. Alternatively, the product container could be filled with a shaped mold in place of the cap. The mold would then be removed after the product solidifies.
Producing a shaped exposed end with a top-fill method is more difficult and requires trimming or cutting the end of the solidified product into the desired shape. With known cylindrical antiperspirant sticks having a round cross-section, the exposed end may be trimmed using, for example, an arrangement of hemispherically shaped cutting edges revolving about the cylindrical axis. However, there is no known way to easily shape the end of a top-filled product if the cross-section of the cylindrical form is oval, elliptical or anything other than circular.
Accordingly, it is an object of this invention to produce a method and apparatus for trimming into a desired shape the end of a solid cylindrical form. It is a further object of this invention to produce a method and apparatus for shaping the end of a solid antiperspirant product having an oval or elliptical cross-section and forming the end into a generally domed shape having an arcuate surface profile along both major and minor axes of the oval or ellipse.